During certain steps in the manufacture of integrated circuits, surface material of, for example, a semiconductor substrate or substrate assembly is removed. Often, photolithographic techniques are used. That is, a surface may be partially masked with the exposed portion of the surface being the area to be removed. Exposed areas of the surface are contacted with a reactive composition in order, for example, to remove a portion of a layer or to form a recess, such as, for example, a contact hole or a via hole in the material.
Dry etching is one example of a process by which surface material can be removed during the manufacture of integrated circuits. Dry etching, sometimes also referred to as plasma etching, can provide, for example, the ability to generate isotropic or anisotropic etch profiles, faithful transfer of lithographically defined photoresist patterns into underlying layers, high resolution, limited handling of dangerous acids and solvents, cleanliness, process control, and ease of automation.
However, components of certain etchant compositions can react to create one or more non-volatile byproduct compounds, which can contaminate gas delivery lines.